Wiktionary
half-halt
n. a specific riding aid given by an equestrian to his horse
Wikipedia
Half-halt
The half-halt is a specific riding aid given by an equestrian to his horse, in which the driving aids and restraining aids are applied in quick succession. It is sometimes thought of as an "almost halt," asking the horse to prepare to halt in balance, before pushing it onward to continue in its gait.
Usage examples of "half-halt".
A quick half-halt jerk to the mouth and a hard seat brought the fractious animal under control.